perilous

adjective

per·​il·​ous ˈper-ə-ləs 

ˈpe-rə-

: full of or involving peril

a perilous journey

perilously adverb

perilousness noun

Synonyms

• dangerous
• grave
• grievous
• hazardous
• jeopardizing
• menacing
• parlous
• risky
• serious
• threatening
• unhealthy
• unsafe
• venturesome

Choose the Right Synonym for perilous

dangerous, hazardous, precarious, perilous, risky mean bringing or involving the chance of loss or injury.

dangerous applies to something that may cause harm or loss unless dealt with carefully.

soldiers on a dangerous mission

hazardous implies great and continuous risk of harm or failure.

claims that smoking is hazardous to your health

precarious suggests both insecurity and uncertainty.

earned a precarious living by gambling

perilous strongly implies the immediacy of danger.

perilous mountain roads

risky often applies to a known and accepted danger.

shied away from risky investments

Examples of perilous in a Sentence

a perilous journey across the mountains

a perilous journey through hostile territory

Recent Examples on the Web

Actually using tariffs to finance a big chunk of the federal government would be a painful and perilous undertaking, budget wonks say. —Arkansas Online, 8 June 2025

Yet the prevailing winds are those of geopolitical rivalry and division, turning our greatest global commons into an increasingly contested and perilous domain. —Sturla Henriksen, Time, 5 June 2025

Luffy sets off from his small village on a perilous journey to find the legendary fabled treasure, ONE PIECE, to become King of the Pirates! —Billie Melissa, MSNBC Newsweek, 2 June 2025

Grease, makeup, sauce, mud, or coffee can prove perilous for your clothing. —Kaitlyn Yarborough, Southern Living, 31 May 2025

Word History

Etymology

Middle English perilous, perelous, borrowed from Anglo-French perilleus, perillous, going back to Latin perīculōsus, from perīculum "test, risk, peril entry 1" + -ōsus -ous

First Known Use

14th century, in the meaning defined above

Rhymes for perilous

• carolus
• garrulous
• querulous
• puberulous

Kids Definition

perilous

adjective

per·​il·​ous ˈper-ə-ləs 

: full of or involving peril

perilously adverb

perilousness noun